The invention relates to a halogen incandescent lamp for operating on line voltage, at least comprising a hermetically sealed, cylindrical bulb made from transparent material, a filling made from inert gas and a halogen additive, a luminous element, a current supply system, and a mount, which is formed from a single-piece support wire, one end region of which is bent away transversely to the lamp axis, and which retains the luminous element in the vicinity of the end of the bulb remote from the pinch, one end of the support wire being fixed in the vicinity of the end of the bulb near the pinch.
Such a halogen incandescent lamp is disclosed, for example, in DE 41 06 851. The described halogen incandescent lamp pinched at one end has what is termed a rodless mount which is bent from a support wire and supports the luminous element at least twice by means of a transverse part. In addition to the transverse part, the mount comprises two limbs which bear resiliently on the inner wall of the bulb, one of the limbs being sealed in the pinch. Given a relatively low number of components, however, the described solution can, be produced technically with much effort and expense only, and so this type of halogen incandescent lamp, which was provided inter alia for general lighting, does not meet the requirements of mass manufacture. These technical difficulties relate, in particular, to the insertion of the mountxe2x80x94with its two limbsxe2x80x94into the bulb. The spring force of the limbs must be overcome in a defined manner during this in order to position the mount accurately in the bulb.
This defined position must subsequently be held, at least until the mount is fixed in the pinch, while maintaining small deviations in position. In the described flat support of the limbs against the inner wall of the bulb, a non-negligible role is played by the tolerances for glass which are usual here, in particular the customary production-induced surface elevations in the case of standard glasses. It is necessary at least for the geometry of the non-sealed limb to be compensated in view of tolerances of the lamp bulb, and this normally requires an additional expenditure.
It is an object of the invention to provide a halogen incandescent lamp which can be produced simply and cost-effectively in technical terms, it being possible for tolerances of the lamp bulb to be disregarded to the greatest possible extent.
The object of the invention is achieved in that a halogen incandescent lamp for operating on line voltage, at least comprising a hermetically sealed, cylindrical bulb made from transparent material, a filling made from inert gas and a halogen additive, a luminous element, a current supply system, and a mount which is formed from a single-piece support wire, one end region of which is bent away transversely to the lamp axis, and which retains the luminous element in the vicinity of the end of the bulb remote from the pinch, wherein a luminous element bent substantially into a U-shape is arranged symmetrically relative to the lamp axis, the luminous element is held twice, that is, at two transversely spaced support points, by the mount in the region of the portion of the luminous element which is arranged transverse to the lamp axis, and one end of the mount is fixed in the pinch.
The invention renders it possible to provide a halogen incandescent lamp whose principal parts, i.e. in particular the lamp bulb and the metal parts to be assembled, in particular the mount and the luminous element, can be prefabricated independently of one another and subsequently connected to one another in a functionally proper and simple way, in particular in conjunction with the manufacture of the pinch.
In a preferred embodiment of the solution according to the invention, one end of the support wire is fixed in the pinch of the bulb so as to be substantially axially parallel between the two parts of the current supply system. This arrangement according to the invention makes optimum use of the available space, which arises in particular from the required minimum spacing of the supply leads.
Under the usual conditions for mass production, namely that the product to be produced is to be realized with the smallest possible expenditure as regards the quality and the quantity of the materials to be used and the further production resources, it is preferred by far for the mount to be formed from an uncoiled, and thus cost-effective, support wire.
It is preferred for the purpose of the invention that the mount comprises a mechanically stable semi-finished product. Such an inherently stable component does not require additional stabilization means, inter alia during mounting, supply, and storage.
A preferred embodiment of the invention relates to the configuration, which is simple according to the invention, of the support wire in the form of a projecting hook whose opening faces the end of the bulb remote from the pinch. This configuration permits a simple threading of the luminous element, and an adequate retention in the mounted state.
A further advantageous embodiment relates to the choice of shape of the luminous element. A luminous element which is a continuous coiled coil, which has at least two luminous sections and at least three non-luminous sections, and of which both ends are at least partial sealed in the pinch, can be manufactured in a particularly cost-effective way and efficiently mounted. For the purpose of the invention, the luminous element, of which the luminous or non-luminous sections are basically not coiled, may be a single coil or a coiled coil.
It is, moreover, favorable for the above mentioned purpose if the luminous element and the supply leads are manufactured from one wire.
It is preferred for the purpose of the invention that the metal inner part of the halogen incandescent lamp, in particular including the luminous element, the mount, the supply leads, the seal foils, and the pin contacts comprise a mechanically stable semi-finished product after the mounting of its above-named parts. Such an inherently stable semi-finished product does not require additional stabilization means, inter alia during final assembly of the halogen incandescent lamp, i.e. in particular the assembly of the glass inner part and the metallic inner part, during supply, and during storage.
The solution according to the invention makes available a halogen light source which can be used in all customary mains voltage ranges, by which a range of approximately 80 V up to 250 V is to be understood, and various power consumptions in the private as well as the professional sphere.